Atividades práticas para o ensino do conceito de tangente no 9° ano

Abstract

We introduce some geometric experiments to the students, and particularly the handling of right-angled triangles, with the clear purpose of inserting, firming and emphasizing the importance, historical and practical, of the concept and meaning of the geometric tangent in an entire acute angle in triangle. Later, the students built a rudimentary theodolite that was used to measure vertical angles of tops inaccessible objects from the ground and consequently the estimate of their heights. The prospect objects were trees, poles, masts, antennas, spotlights, among other more familiar to the students of the ninth grade in elementary school.